Drive train design for electric driven vehicles

ABSTRACT

A powertrain arrangement for a transverse mounted motor for an electric powered automotive passenger vehicle including opposing wheel shafts for powering two parallel mounted wheels, the shafts rotating about a first axis, the shafts having at least one end torsionally connected with a differential, an electrical rotor torsionally connected with the wheel shafts via a planetary gear train, an electrical stator surrounding the rotor, a casing supporting the rotor and the wheel shafts, the casing encompassing the stator, the casing having a floor forming a lubricant reservoir, and a baffle located in the lubricant reservoir, the baffle having barriers generally transverse to the first axis and at least one of the barriers having a lower window allowing fluid communication underneath the barrier.

FIELD OF THE INVENTION

The present invention relates to hybrid electric and electric driven automotive vehicles.

BACKGROUND OF THE INVENTION

To reduce carbon emissions and to lower the reliance upon foreign oil, various designs for hybrid electric and electric driven vehicles have been brought forth. To increase mechanical efficiency, various designs for hybrid electric and electric driven vehicles have a transversely mounted motor or motor generator in the vehicle (the term “motor” as used hereinafter refers to motors or motor generators). Typically, the motor is connected to the vehicle wheels via some type of gear train which is inclusive of a differential. The gear train and differential require oil lubrication. The oil lubrication system typically includes a reservoir commonly referred to as the oil pan.

To minimize the energy required to move an automotive vehicle, most vehicles have attempted to lower the spatial envelope of the vehicle to minimize the air resistance of the vehicle as it moves forward. However, for road clearance purposes it is desirable that the floor of the vehicle and of the vehicle power plant is positioned as high as possible. Furthermore, it is desirable for the power plant and power train of a hybrid electric or electric vehicle be as small as possible to help compensate for the spatial requirements of the vehicle battery. To help minimize the spatial requirements, typically the motor of the vehicle is placed within the same casing of the powertrain that connects the motor or motor generator with the vehicle wheels. The level of lubricant within the casing should be low enough that the lubricant does not enter into the air gap between the rotor of the motor and a stator surrounding the rotor. Typically, this is achieved by having oil pan strategically placed underneath the stator with enough volume to ensure that the oil does not reach a level to approach the air gap the stator and the rotor. However, as mentioned previously it is desirable that the oil pan be as shallow as possible to provide for better road clearance of the vehicle. In normal movement of the vehicle, the above noted constraints are easily met. However, when the vehicle is in a high speed turn the fluid within the casing is accelerated to an outboard side of the vehicle. The lateral acceleration can cause the fluid to rise to a level wherein it can reach the air gap between the motor rotor and stator. It is desirable to provide an arrangement for a transverse mounted motor for an electrically powered automotive passenger vehicle wherein fluid acceleration due to cornering maneuvers is restrained from reaching levels wherein it may enter into the air gap between rotor and stator without enslavement to a deep oil pan design configuration. It is also desirable to provide the above noted vehicle arrangement wherein fluid acceleration does not allow the fluid lubrication pump intake to be starved of oil when the vehicle is completing a cornering maneuver.

SUMMARY OF THE INVENTION

To make manifest the above noted and other gainful desires, a revelation of the present invention is brought forth. In a preferred embodiment, the present invention endows a freedom of a powertrain arrangement for a transverse mounted motor for an electric powered automotive passenger vehicle comprising opposing wheel shafts for powering two parallel mounted wheels, the wheel shafts are rotating about a first axis. The wheel shafts have at least one end torsionally connected with a differential. An electrical rotor is torsionally connected with the wheel shafts via a planetary gear train. An electrical stator is surrounding a rotor. A casing is provided that supports the rotor and the wheel shafts. The casing encompassing a stator, the casing has a floor forming a lubricant reservoir. A baffle is located in the reservoir, the baffle has barriers generally transverse to the first axis, and at least one of the barriers has a lower window allowing fluid communication underneath the barrier.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a sectional view of a preferred embodiment powertrain arrangement of the present invention with a baffle removed for clarity of illustration;

FIG. 2 is a view similar to that of FIG. 1 illustrating acceleration of lubrication fluid due to a cornering maneuver of the vehicle shown in FIG. 1;

FIG. 3 is a view similar to that of FIG. 1 illustrating acceleration of lubrication fluid due to a cornering maneuver of the vehicle shown in FIG. 1;

FIG. 4 is a perspective view of the powertrain arrangement of FIG. 1;

FIG. 5 is a partial side elevational view of the powertrain arrangement of FIG. 1 with a baffle removed for clarity of illustration;

FIG. 6 is a section perspective view of the powertrain arrangement shown in FIG. 1;

FIG. 7 is a side elevational view of the powertrain arrangement shown in FIG. 1 illustrating the baffle with portions of the lube pump filtering system not shown for clarity of illustration;

FIG. 8 is a perspective view of the baffle shown in FIG. 7;

FIG. 9 is a top plane view of an alternate preferred embodiment baffle;

FIG. 10 is a view taken along lines 10-10 of FIG. 9;

FIG. 11 is a front plan view of an alternate preferred embodiment baffle;

FIG. 12 is a view taken along lines 12-12 of FIG. 11;

FIG. 13 is a top plane view of an alternate preferred embodiment baffle;

FIG. 14 is a view taken along lines 14-14 of FIG. 13;

FIG. 15 is a view taken along lines 15-15 of FIG. 13;

FIG. 16 is an alternate preferred embodiment baffle;

FIG. 17 is a view taken along line 17-17 of FIG. 16;

FIG. 18 is an alternate preferred embodiment baffle; and

FIG. 19 is a view taken along line 19-19 of FIG. 18.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Referring to FIGS. 1 through 6 a preferred embodiment power train arrangement for a transverse mounted motor for an electric powered automotive passenger vehicle is provided (as used hereinafter the term “motor” additionally refers to motor generators and the term “electric vehicle” additionally refers to hybrid electric vehicles). The arrangement 7 has opposing wheel shafts 14 and 16. Parallel mounted wheels 10 and 12 are powered by and connected to wheel shafts 14 and 16 respectively. The wheel shafts 14 and 16 rotate about a first axis 18. The wheel shafts 14 and 16 each have an end torsionally connected with a differential 20.

Differential 20 is fixedly and or integrally connected with a planetary gear set carrier 22. The carrier 22 mounts three carrier pins 24 (only one shown in FIG. 1). Rotatably mounted on the carrier pin 24 is a carrier gear 26 which is engaged with ring gear 28. End carrier gear 26 is fixably connected with and powered by a planetary gear 32. Three planetary gears 32 (only one shown in FIG. 1) are engaged by a sun gear 34. The sun gear 34 is integral with or fixedly connected with a hollow shaft 38. Hollow shaft 38 at an end opposite the differential 20 is torsionally connected with a rotor shaft 40. The rotor shaft 40 is connected with magnetic portion 42. The magnetic portion 42 is part of the rotor assembly. The magnetic portion includes lamination fabricated from thin steel sheets in combination with magnets. Surrounding magnetic portion 42 is a coil winding stator assembly 46. The stator assembly is fabricated from metal laminating and coil windings. An air gap 48 exists between the rotor magnetic portion and the stator assembly coil windings 46.

The differential 20 is supported by roller bearing 54. The bearing 54 is supported on a right central wall 60. A bearing 56 supports the right side of rotor shaft 40. On the left side is a support housing 62. Support housing 62 has a bearing 64 to support the left side of the rotor shaft 40. A parking brake gear 70 is fixedly connected with the shaft 38. A parking brake latch arm 74 (FIG. 5) is selectively engaged with the parking brake gear teeth 76 to place the vehicle in park. A lubricant filter casing 78 is provided having an intake 80 help up on filter casing legs 82 from a floor 84 of the casing 85. The casing floor 84 forms the bottom of the lubricant storage area or oil pan. The floor 84 has a slight tilt towards the filter casing 78 end of the casing 85. The floor 84 tilt is preferably 1 to 2 degrees. Preferably the casing floor 84 will be located at a distance from the rotor 18 equal to or less than two-thirds the diameter of the rotor.

To keep the oil from rising along the lines shown in FIGS. 2 and 3 due to lateral acceleration of the vehicle due to cornering or other maneuvers, a baffle 100 is provided. Excessive oil rise can temporarily starve the lubrication pump intake 80. Also, excessive oil rise can possibly foul components of the motor. The baffle 100 has a series of generally parallel spacial barriers 104, generally transverse to the first axis 18. Most if not all of the barriers 104 along their lower end have a series of crescent-shaped windows 106 functioning as oil migration channels. The baffle 100 can additionally have a plurality of barriers 108 generally parallel to the first axis 18. The barriers 104 on the outboard edges 110 of the casing 85 can be contorted to match a lateral edge 87 for the casing. The baffle 100 can be slid into the casing 85. In operation, the lubricant oil is restrained laterally by the baffle and the oil level rise due to lateral acceleration is limited to an amount to ensure that the pump intake 80 is not starved and that the components of the motor are not fouled by the lubricant oil.

In an example shown in FIGS. 9 and 10, the baffle 200 has transverse barriers 202 on an incline that is directed toward a longitudinal centerline 205 of the vehicle that the casing 85 is placed in (in other words, the transverse barrier 202 on the passenger side of the vehicle is slanted bottom to top towards the driver's side of the vehicle and vice versa). The barriers 202 have windows 203.

Referring to FIGS. 11 and 12, an alternate preferred embodiment barrier has turbine-shaped transverse barriers 217. The barriers 217 are curvilinear in all three geometric axes so that fluid accelerated into the transverse barrier 217 by lateral acceleration of the vehicle is imparted along vector 219. Vector 219 has an upward horizontal flow component 221, lateral flow component 223, and reverse flow component 225. The flow vectors of the various transverse barriers of a given baffler can be varied to provide maximum dampening of fluid movement.

FIGS. 13-15 provide another embodiment baffle 300 having transverse barriers 301 extending from the floor, having sinusoidal shape. The baffle also has a series of alternating sinusoidal shaped barriers 303 extending from a ceiling of the baffle or from the bottom of the stator assembly. The barriers 301 have windows 305 between the apices 307 (along the axis 18) of their sinusoidal shape. The up and down flow 309 over the transverse barriers 301 and 303 and the flow 313 through the windows 305 dampen the acceleration of the transverse flow when the vehicle is cornering.

Referring to FIGS. 16 and 17, a transverse barrier 401 forms a wall with a singular or multiple portals 403. A stopper 405 is compliantly positioned and biased away from the portal 403 by a spring 407 to throttle flow through the portal 403 by a spring 407 to throttle flow through the portal 403. Fluid pressure resultant of fluid acceleration causes stopper 405 to be pushed toward the portal 403 and throttle the flow therethrough. When the vehicle exits a curve, the spring 407 will return the stopper to allow free flow of oil past the portal 403.

Referring to FIGS. 18 and 19, a barrier 501 has a portal 503. A pivotal flap 507 covers portal 503. Pivotal flap 507 is biased open by a weight 511 on a lever 509 that is torsionally connected with the flap 507. Barrier 501 operates in a manner similar to that of barrier 401.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. 

1. A powertrain arrangement for a transverse mounted motor for an electric powered automotive passenger vehicle comprising: opposing wheel shafts for powering two parallel mounted wheels, said shafts rotating about a first axis, said shafts having at least one end torsionally connected with a differential; an electrical rotor torsionally connected with said wheel shafts via a planetary gear train; an electrical stator surrounding said rotor; a casing supporting said rotor and said wheel shafts, said casing encompassing said stator, said casing having a floor forming a lubricant reservoir; and a baffle located in said lubricant reservoir, said baffle having barriers generally transverse to said first axis and at least one of said barriers having a lower window allowing fluid communication underneath said barrier.
 2. A powertrain arrangement as disclosed in claim 1 wherein said baffle additionally has barriers generally parallel to said first axis.
 3. A powertrain arrangement as disclosed in claim 1 wherein a plurality of said baffle transverse barriers have lower windows.
 4. A powertrain arrangement as disclosed in claim 1 wherein said rotor has first diameter and said casing floor is distanced from said first axis at a distance equal to or less than 67% of said diameter of said rotor.
 5. A powertrain arrangement as described in claim 1 wherein said baffle transverse barriers are curvilinearly configured to impart flow to fluid flowing toward said barrier in a direction away from said barrier taken from one or more of the group of upward, reverse and lateral flow directions.
 6. A powertrain arrangement as described in claim 1 wherein said baffle has barriers extending down from a ceiling alternating with barriers extending from a floor.
 7. A powertrain arrangement as described in claim 1 wherein said baffle barrier has a sinusoidal shape.
 8. A powertrain arrangement as described in claim 6 wherein said baffle lower and upper barriers have a sinusoidal shape.
 9. A powertrain arrangement as described in claim 7 wherein said barrier has windows between apices of said barriers' sinusoidal shape.
 10. A powertrain arrangement as described in claim 1 wherein said barrier forms a wall with portals allowing flow through said wall, and wherein an increase of fluid pressure throttles flow through said wall.
 11. A powertrain arrangement as described in claim 10 wherein said portal is biased by at least one of a group of compliant loading or loading by weight.
 12. A powertrain arrangement for a transverse mounted motor for an electric powered automotive passenger vehicle comprising: opposing wheel shafts for powering two parallel mounted wheels, said shafts rotating about a first axis, said shafts having at least one end torsionally connected with a differential; an electrical rotor torsionally connected with said wheel shafts via a planetary gear train; an electrical stator surrounding said rotor; a casing supporting said rotor and said wheel shafts, said casing encompassing said stator, said casing having a floor forming a lubricant reservoir; a baffle located in said lubricant reservoir, said baffle having barriers generally transverse to said first axis and a plurality of said barriers having a lower window allowing fluid communication underneath said barrier; and wherein said rotor has first diameter and said casing floor is distanced from said first axis at a distance equal to or less than 67% of said diameter for said rotor.
 13. A method of powering an electric powered automotive passenger vehicle comprising: providing opposing wheel shafts for powering two parallel mounted wheels, said shafts having at least one end torsionally connected with a differential; providing a transverse mounted electrical rotor torsionally connected with said wheel shafts via a planetary gear train; providing an electrical stator surrounding said rotor; providing a casing supporting said rotor and said wheel shafts, said casing encompassing said stator, said casing having a floor forming a lubricant reservoir; and providing a baffle located in said lubricant reservoir, said baffle having barriers generally transverse to said first axis and at last one of said barriers having a lower window allowing fluid communication underneath said barrier.
 14. A method as disclosed in claim 13 wherein said baffle has a portal, and said portal throttles flow upon acceleration of fluid.
 15. A method as disclosed in claim 14 wherein said portal is compliantly biased to an open position.
 16. A method as disclosed in claim 14 wherein said portal is biased by a weighted lever. 